Gastroesophageal reflux disease, or GERD, is a medical condition caused by the repeated backup or regurgitation of food and digestive fluid from the stomach into the esophagus. The most common symptoms suggestive of GERD are heartburn or acid indigestion. GERD can damage esophageal tissues, raising the risk of serious problems such as cancer of the esophagus. It is estimated that ten percent of Americans suffer from GERD on a daily basis.
GERD occurs when a small ring of muscles called the lower esophageal sphincter (“LES”) do not function properly. For example, at rest, the LES may maintain a high-pressure zone between 10 and 30 mm Hg above intragastric pressure. However, some patients suffering from GERD have an LES closing pressure of only 5 mm Hg. A weak or malfunctioning LES allows acidic stomach contents to back up into the esophagus. As the stomach contents flow back into the esophagus, the lining of the esophagus becomes irritated, creating a burning feeling in the chest. Left untreated, GERD can lead to frequent heartburn, difficulty swallowing, coughing, hoarseness, and more serious complications, such as narrowing of the esophagus, bleeding and a pre-cancerous condition called Barrett's esophagus.
There are a variety of treatments for GERD. The most common treatment involves lifestyle changes. For example, smoking, drinking, obesity, overeating, and diets high in fat and coffee all increase the chances of contracting GERD. There are also a wide variety of drugs that treat the symptoms associated with GERD. For example, antacids neutralize excess acid in the stomach to reduce irritation of the esophagus. H-2 receptor blockers reduce the amount of digestive acid that the body produces. An example of a relatively new class of drugs are Proton Pump Inhibitors that reduce acid production by affecting the final pathway of gastric acid secretion. Another class of drugs are Prokinetic agents, which treat GERD by shortening the digestion time and tightening the pressure that the LES places on the esophagus. Unfortunately, many of these drugs come with side effects, including nausea, constipation, diarrhea, cramps and potentially harmful interactions with other medications. Further, most of these medications do not treat the underlying cause of GERD, a malfunctioning LES.
Although the above treatments may be successful for some patients, surgery may be considered if relief is not obtained. The aim of surgery is often to restore the function of the LES to close during digestion. One example of a surgical procedure is laparoscopic fundoplication. After expanding the abdomen with gas, a surgeon inserts a laparoscope through an incision. Attached is a small camera that projects an internal image onto a monitor. Using this image, the surgeon reinforces the LES by wrapping the upper portion of the stomach around the lower portion of the esophagus.
An alternative to surgery has recently gained recognition, in which the submucosal layer of the lower esophagus is augmented with one of a variety of implant materials, including polytetrafluoro-ethylene (PTFE) pastes and collagen gels. For example, Rupp, “Endoscopic Antireflux Techniques,” reports GERD treatments in which PTFE, collagen and hylan gel were injected into the submucosal layer of the lower esophagus. Shafik, “Intraesophageal Poltytef Injection for the Treatment of Reflux Esophagitis” and “Tissue Reaction to PTFE Pastes—A Review of the Literature,” also report GERD treatments in which PTFE was injected into submucosal lower esophageal tissue sites. However, Rupp, Shafik and the Literature review report problems with PTFE pastes, including migration from the injection site and granuloma response at injection and migration sites. Thus, there is a need in the art for a method of augmenting submucosal tissue sites of the lower esophagus using PTFE-free particulate matter.